The C-PACE Project (Communications Processes for Accountable Care Enhancement) will develop a new and innovative form of social computing that is customized for the care of frail, elderly patients. A successful C-PACE system will improve patient-centered health care, reduce medical errors, and provide the kind of data that CMS, third party payers, Accountable Care Organizations and other health care organizations need in order to monitor clinical outcomes. C-PACE is ideally suited to the aging population toward which it will be initially targeted. These complex patients are constantly shuttled back and forth between providers and venues of care. But the information needed to track and care for such individuals does not necessarily follow them - even, surprisingly, in the era of electroni health records (EHRs). How could such a thing possibly happen in the digital age? The answer is deceptively simple. EHRs sit in silos, geared for billing and designed to document single events of care. They embody information that may describe care episodes and associated costs, but rarely include certain critical thought processes. Such thought processes, including patient preferences, are needed by down-stream providers to understand, literally, what needs to happen next. Today, communications about transitions of care, information hand-offs, clinicians' communications to give one another heads-ups, or to pick each other's brains are key pieces of the care process that are not documented and that, as a result, just get lost. C-PACE is a software tool that captures, in a lasting digital record, these clinical communications about patients that collectively form care coordination. The science behind C-PACE draws from different disciplines of medicine and technology including geriatrics, human factors, medical informatics, social network analysis, and user interface design. Phase I of this interdisciplinary effort will show whether the building of such a system is feasible, by developing and assessing a user-centered C-PACE human- computer interface, an underlying data model, and a data mining capability. C-PACE can rewrite the rule-book by taking what's always been under the radar -- care-coordination -- and making it visible, well-supported, and accountable.